Hi Rani,

You don't need to apply to each IIM individually. All the IIMs where your CAT 2017 score is meeting the minimum cutoff criteria will call you for the next rounds of the selection process. Please go to the link given below to know more:

https://bschool.careers360.com/articles/which-b-schools-can-i-get-if-my-cat-percentile-between-90-and-100

All the best.